Investigation of negative resistance induced by directional scattering in a two dimensional electron gas /

Official URL: http://risc01.sabanciuniv.edu/record=b1160392 (Table of Contents)

In the last decades, it became possible to manufacture high mobility twodimensional conductors. The study of electron transport in such two dimensional conductors has led to discovery of many new physical phenomena, two of which were awarded with Nobel prizes. The reduction in the dimensions of a conductor drastically changes the scattering properties of carriers. Intercarrier scattering angle is also severely reduced in two dimensions. Recently, it was shown that this kind of directional scattering can be exploited to achieve electron multiplication and absolute negative resistance in a three terminal configuration. Experimental results suggest that such an effect should boost as the device size shrinks and can be useful to fabricate compact high frequency sources that are not yet within the reach of conventional semiconductor devices. The purpose of this thesis is to extend further the experimental study of such phenomena, and in particular, to understand its dependence on the device size. For this a new fabrication method has been developed. This method gives a greater flexibility to shrink the device size down to sub-microns. The new generation of fabricated devices produce high electron multiplication ratios up to 5.